Digital Advent Calendar - Day 21

I see a lot of people cropping their photos and then resaving the original thus losing some of the original file information.  I suggest you keep your original file, make a working copy of that file and then crop based on the final output size you want to produce.  This way you have leeway in the event you want to specify a different print size at a later date.  I recommend Adobe Photoshop Lightroom highly due to its non-destructive editing capabilities.